Carotenoids are a group of pigments that are characterized by color including and ranging from yellow to red. Carotenoids are commonly produced by a wide variety of plant materials and most commonly associated with plants such as tomatoes, carrots and peppers.
Lycopene and its precursors, phytoene and phytofluene, are commonly found in tomatoes and lycopene is the predominant source of the bright red color associated with tomatoes. Phytoene is a precursor of phytofluene, lycopene and other carotenoids, and is also found in high concentrations in tomatoes. Lycopene is generally present in the plasma of the human body. Carotenoids are known to have antioxidant properties and consequently, provide numerous beneficial health effects including reduction of the potential risks of cardiovascular diseases, and cancers, as well as slowing and/or reversing the degenerative effects of aging on various human physiological activities.
Phytosterols (plant sterols) are a group of steroid alcohols, or phytochemicals which are naturally occurring in plants, and are the counterparts of cholesterol in animal products. The structure is similar to that of cholesterol with some modifications. These modifications involve a side chain and include the addition of a double bond and/or methyl or ethyl group. The most common dietary phytosterols are β-sitosterol, Campesterol and Stigmasterol. The Western diet contains 80 mg β-sitosterol/day. In the Finnish diet, 140-175 mg/day (see Valsta et al., British Journal of Nutrition (2004), 92, 671-678), whereas vegetarian and Japanese diets contain 345 and 400 mg/day, respectively. The best dietary sources of phytosterols are unrefined plant oils, seeds, nuts and legumes. Processing of plant oils (such as refining and deodorization) reduces phytosterol content, but the loss varies with the type of oil. However, hydrogenation of refined oils has little effect on phytosterol content.
Plant sterols and stanols effectively reduce serum LDL cholesterol and atherosclerotic risk (1). In addition, potential effects of plant sterols and stanols on other metabolic processes remain to be elucidated (2).
Phytosterols are not endogenously synthesized in the body, and therefore they are derived solely from the diet by means of intestinal absorption. The plasma phytosterol level in mammalian tissue is usually very low, primarily due to poor absorption from the intestine and faster excretion from the liver as compared to cholesterol (3). Although absorption of plant sterols and stanols (0.02-3.5%) is low compared to cholesterol (35-70%), small amounts are found in the blood and may influence certain physiological functions. Intestinal phytosterol absorption is selective; in animals Campesterol is better absorbed than β-sitosterol, while Stigmasterol is only absorbed minimally. Only 0.3-1.7 mg/dl of phytosterols are found in human serum under normal conditions, in spite of daily dietary intakes of 160-360 mg/day. Total plasma plant sterol concentrations in healthy adults range from 7 μmol/L to 24 μmol/L, which accounts for less than 1% of total plasma sterol concentrations (4). Other researchers have reported that β-sitosterol and Campesterol were the only two phytosterols detectable in blood (1, 5).
The most common phytosterols in tomato oleoresin are β-sitosterol, Campesterol and Stigmasterol as shown below in Table 1, as determined in accordance with the procedure set forth in Example 2 hereof.
TABLE 1Levels of Phytosterols in Tomato OleoresinTotal Phytosterols (mg/100 g)650-1100Campesterol (mg/100 g)150-220Stigmasterol, (mg/100 g)250-480β-Sitosterol, (mg/100 g)250-400
The uncontrolled production of reactive oxygen species (ROS) and arachidonic acid (AA) metabolites contributes to the pathogenesis of cardiovascular disease and cancer. Inflammatory cells infiltrated in the atheroma plaque or tumor, are a major source of ROS and eicosanoids. Therefore, the effects of beta-Sitosterol, a phytosterol from olive oil, on ROS levels such as superoxide anion (O2(−)), hydrogen peroxide (H2O2), and nitric oxide (*NO) have been studied (6). AA release and eicosanoid production by phorbol esters (PMA)-stimulated macrophages (RAW 264.7 cells) has also been studied. Beta-sitosterol was shown to decrease the O2(−) and (H2O2) production induced by PMA, and exerted its effects 3-6 hours after preincubation. Beta-sitosterol also reduced the *NO release induced by PMA, which was correlated with the impairment of inducible nitric oxide synthase (iNOS) levels (6).
Prostate cancer and benign prostatic hyperplasia (BPH) are aging-related conditions that affect prostate gland physiology and impair urinary function in men. As men age, their prostate glands slowly enlarge causing (a) obstructive symptoms exemplified by weak and/or intermittent urinary streams, a sense of residual urine in the bladder after voiding, dribbling or leakage at the end of urination, and/or (b) irritative symptoms as exemplified by urgency of micturation, increased frequency of urination, and uracratia. Obstructive and irritative urinary symptoms are commonly referred to as lower urinary tract symptoms (LUTS). The current treatment of prostate cancer, BPH and LUTS symptoms consist of drug therapy, and in extreme cases requires major surgery. The two primary drug classes used are alpha-blockers and 5-alpha-reductase inhibitors, which should be taken for life in order to obtain persistent efficacy. When surgery is conducted, the results are usually positive, but there are certain risks associated with such surgical operations.
US Patent Publication 2005/0031557 (“the 557 Publication”) describes an oral composition containing β-carotene, lutein and lycopene, and includes, as potential added ingredients, phytoene and phytofluene, for use as sun protection. This publication does not indicate a preference for a specific amount of either of phytoene or phytofluene relative to lutein or any of the following list of phytochemicals consisting of alpha-carotene, astaxanthin, alpha-cryptoxanthin, beta-cryptoxanthin, zeaxanthin, phytoene, phtyofluene, gamma-carotene and neurosporin. The '557 Publication does not provide a reason for including any of the members of that list in the composition.
Epidemiologic and experimental studies suggest that dietary phytosterols may offer protection from most cancers in Western societies, such as colon, breast and prostate cancer. The possible mechanisms by which phytosterols offer this protection may include the effect of phytosterols on membrane structure, the function of the tumor and host tissue, signal transduction pathways that regulate tumor growth and apoptosis (8), and immune function (9) of the host. Also, the cholesterol metabolism by the host, beta-sitosterol supplementation, reduced cholesterol and other lipids in tumor cell membrane (10). In addition, Table 2 below summarizes the results of several in vitro studies or the effects of phytosterols on human cancer cell lines:
TABLE 2In vitro studies with various cancer cell linesCellconcentrationlinetissuephytosterol(μM)parameterRef.HT-29humanβ-sitosterol16growth(10)coloninhibitioncancerLNCaPhumanβ-sitosterol16growth(11)prostateinhibition;cancerreduced PSAlevelsMDA-humanβ-sitosterol16growth(12)MB-breastinhibition231cancerCampesterol16growth =unchangedcholesterol16growth =unchangedMCF-7humanSIT0.001 to 150growth(13)breastincreasecancer
Additional studies have been performed in order to identify possible mechanisms by which two common phytochemicals, resveratrol and beta-sitosterol, inhibit the growth of human prostate cancer (14). In these studies, human prostate cancer cells (PC-3 cells) were supplemented with 50 μM resveratrol or 16 μM beta-sitosterol, alone or in combination, for up to 5 days (14). The combination of the two compounds resulted in greater inhibition of growth than either compound alone. Based on these data, it was concluded that these phytochemicals may induce the inhibition of tumor growth by stimulating apoptosis and arresting cells at different locations in the cell cycle, and that the mechanism may involve alterations in the production of ROS and prostaglandin (14).
Additional reports also indicate that a combination of phytosterols and omega-3 fatty acids (n-3) further reduces cardiovascular risk factors (15).
Plant sterols and stanols are reported as lowering the plasma concentrations of hydrocarbon carotenoids, but not those of the oxygenated carotenoids and tocopherols (3, 16). In one report, the ability of plant sterol esters (PSE) in salad dressing to modify plasma lipids and carotenoids was determined in 26 men and 27 women who were fed controlled, weight maintaining, isocaloric diets (17). Consumption of 3.6 g of PSE resulted in decreases in LDL cholesterol (9.7%) and triglycerides (7.3%) but no change in EDL cholesterol was observed. Total plasma carotenoids decreased 9.6% with consumption of PSE. Specifically, there were significant decreases in beta-carotene, alpha-carotene, and beta-cryptoxanthin. Plasma carotenoids on all diets remained within normal ranges. In another study, the data indicate that plant free sterols and PSEs reduced the bioavailability of beta-carotene by approximately 50% and that of alpha-tocopherol by approximately 20% (18).
Notwithstanding the above reported studies, there remains the need for pharmaceutical compositions comprising carotenoids, e.g., lycopene, for therapeutic use.